March 9, 2017 is the official rollover date for E-mini futures. On that date, you can switch to the ES 06-17 (June 2017) contract. As of this moment, most traders are still trading the March contract, which currently has over 6x the volume compared to the 06-17 contract. Of course, the volume will transfer to the 06-17 contract in the coming days. Some traders prefer to trade the contract with the greatest volume. Others prefer to switch on the exact roll date, no matter what. Click here for the CME page that shows the volume. On the roll date, expect a significant amount of volume to transfer over. After March 9, the next roll date is June 8, 2017.
As a reminder, here’s how to roll over your contracts with NinjaTrader 7. If you use NinjaTrader 8, click here. In NinjaTrader 7, begin by going to Tools > Instrument Manager
1. In the name box, type in the name of the instrument you wish to roll over (e.g. ES)
2. Click Search
3. A row should appear for the instrument you searched for. Click on the row so it becomes highlighted. If you’re doing this on or after Mar. 9, notice how NinjaTrader automatically knows the new contract to use. If you are rolling over early, you may need to select 06-17 from the Expiry list.
4. Click the button that has a black arrow that points to the left. Doing so will add the new contract period to the list of selectable instruments. If desired, you can select old contracts from the left list and then click the right black arrow button to remove them.
5. Once satisfied, click OK at the bottom.
Now, go to an existing chart or open a new chart. You should be able to select the new contract period.
This picture shows the steps from above: